A Case of Natural Killer Cell Leukemia Misdiagnosed as Tuberculous Lymphadenopathy

Abstract

194Natural killer (NK) cell neoplasms are a group of rare but highly malignant tumors. We report here one case of NK cell leukemia. A 54-yr-old woman presented with a 2-month history of progressive left neck mass. Based on the positive result of tissue PCR for Mycobacterium tuberculosis, she was at first diagnosed with tuberculous lymphadenopathy. After two weeks, she developed generalized lymphadenopathy, hepatosplenomegaly, fever and anemia. Subsequent evaluation was performed including bone marrow aspiration and biopsy. Peripheral blood smear showed leukoerythroblastic features with 31% blasts. Bone marrow was packed with agranular blastoid cells, which were periodic acid-Schiff (PAS) positive and myeloperoxidase (MPO) negative. Immunophenotyping showed that these cells were positive for CD45 and HLA-DR, whereas negative for CD3, CD5, CD7, CD10, CD13, CD14, CD19, CD20, CD22, CD33, CD34, and CD61. Because of the absence of the markers of T-cell, B-cell, and myeloid lineage-specific antigens, we added CD16/56 for the immunophenotyping and the blasts were positive (94%). The tumor cells of biopsied lymph node were only positive for CD56, consistent with NK cell lymphoma. Epstein-Barr virus (EBV) was not detected by RNA in situ hybridization. Culture for M. tuberculosis was negative. Thus this patient was diagnosed with blastic NK cell lymphoma/leukemia involving bone marrow and lymph node. (Korean J Lab Med 2009;29:194-8)

Development of a Platform for Natural Killer Cell Therapy with Antiviral Efficacy

“…자연살해세포(NK세포)는 본래 바이러스 또는 종양 세포에 자연적인 세포독성을 가지는 큰 과립 림프구 로 설명되었다 [4,5] . NK세포는 나중에 비정상 세포에 대한 세포독성과 사이토카인 생성을 통한 다른 면역 세포의 활성을 증가시키는 능력을 모두 가진 별도의 림프구 계통으로 인식되었다 [4,6] .…”